1. Field of the Invention
The present invention relates to a substrate carrying apparatus for carrying processed substrates, particularly to a substrate carrying apparatus in which locating of the carried substrates is possible.
2. Description of the Background Information
A known substrate carrying apparatus is described in Japanese Laid-Open Patent Publication (Kokai) No. HEI 4-65149 (1992). The substrate carrying apparatus disclosed in the above-mentioned publication comprises a carrying arm including a plurality of pivot joints, a substrate receiver provided on a head of the carrying arm, and a substrate engaging portion provided at a head of the substrate receiver. Further, a locating member is provided above the substrate receiver extending in the direction of the width of substrate receiver, and is supported via the substrate receiver by a connecting portion, in such a manner that the locating member can move forward or backward by the revolution of the substrate receiver. As for the X-axis direction of substrate, the locating member advances in such a manner that the substrate is inserted between the locating member and the substrate engaging portion, by which the locating of substrate is made. As for Y-axis direction of the substrate, the substrate is inserted between pushing plates provided at both ends of the locating member, by which the location of the substrate is accomplished.
In recent years, processed substrates are becoming larger. This is due to the productivity increase in the production of semiconductors, or to the increased demand for large-sized liquid crystal display substrates for LCD liquid displays. Manufacturing larger substrates means that the substrate itself becomes heavier, and the load applied on the carrying arm becomes higher.
However, in the apparatus disclosed in the above-mentioned publication, since the locating member is supported by the substrate receiver via the connecting portion, the weight of the substrate receiver is applied on the carrying arm, and the carrying arm is thereby bent. Accordingly, there is a fear that the carrying of the substrate is hindered. Furthermore, the load of the carrying arm applied to the driving means for driving the carrying arm is increased.
Additionally, in the case of locating substrates, it is desirable to reduce the contacting area with the substrate to as little as possible in order to prevent contamination of the substrate. However, in the above-mentioned conventional example, each of the members for locating the substrate relative to the X-axis, the members for locating the substrate relative to the Y-axis, and the substrate-receiving part, are brought into contact with the substrate. Accordingly, the total contacting area becomes larger.
Still further, since the shape of the substrate receiver itself conforms to the shape of the substrate, the larger a substrate becomes, the larger the substrate receiver becomes. Therefore, bending of substrate receiver is caused even by empty weight, by which the head of the substrate is bent, and so there is a fear that carrying of the substrate is hindered.